I have just noticed that the connection used for logins by concertina.net is not encrypted:
"Not secure | www.concertina.net/forums/"
This is from the Chrome browser, Firefox is more explicit - it warns me not to go to the site.
Is the forum software being used fully up to date with all security patches?
The takeaway for everyone right now is to be sure to use a unique password for this site alone so that if it is compromised then it will only be your concertina.net account and not your bank or PayPal account.